[fpc-devel] Episode 4. Addressing and it's limits Part Two

rvmartin2 at ntlworld.com rvmartin2 at ntlworld.com
Wed Feb 8 15:16:50 CET 2012


Hans-Peter Diettrich <DrDiettrich1 at aol.com> wrote the following on 08/02/12 11:28:49:
> Mark Morgan Lloyd schrieb:
> > Hans-Peter Diettrich wrote:
> >> steve smithers schrieb:
> >>
> >>> Regardless of what you may believe, FreePascal is not the first 
> >>> compiler to be
> >>> implemented on 370 architecture.
> >>
> >> I.e. you can study how they create code, before you reinvent the wheel 
> >> :-)
> > 
> > :-) Had occurred to me as well, although obviously a lot is dictated by 
> > FPC's higher-level parsing and structure.
> 
> This should not be a problem. It's up to the code generator to define 
> its own strategies for allocating space for code and data items, and how 
> to address them in generated code. The parse tree tells the back-end 
> *what* should be done, the back-end then has to know *how* to do it.
> 
> > Might still be very useful for 
> > getting calling conventions etc. right.
> 
> The implementation of calling conventions is up to the code generator as 
> well. You can invent your own conventions, and map them to any 
> predefined one. As a starting point it's sufficient to support only one 
> calling convention, the one for system calls. More conventions for 
> calling other external libraries may be required, depending on the 
> target OS conventions.

Where can I find details of the input to the back-end?
I'd like to have a crack at generating assembler code for VM/SP. 



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